This invention relates to an apparatus for the production of molded bodies of expandable plastics, particularly polyurethane, in which the parts of a two-piece mold, wherein the molded bodies are expanded, are attached to two clamping plates of a mold holder or support which is pivotable about at least one axis. The clamping plates are arranged one above the other and are pivotable on parallel axes, and special holding devices are provided to prevent the clamping plates and the mold support from swinging back or from undergoing any other undesired movement.
In a known apparatus (U.S. Pat. Nos. 3,981,671 and 4,007,679) a gear segment and spring pawl serve as the special holding device. These elements are formed and mounted in a very special manner, and the device is said to have an extraordinarily high load capacity. But it is a disadvantage of this type of holding devices that during the operation of the apparatus they cause significant noise and do not allow a stepless pivoting and other movement of the clamping plates and the mold support. The noises are particularly unpleasant because in full use of the apparatus they occur every 2 to 3 minutes and reach about 75 to 80 dB(A). The noise annoyance to operating personnel of the apparatus is thus substantial.